Good afternoon. I imagine you've found an answer to your question, but we've tested and found that Pidgin works with CUP. We have run into a small problem that I'm currently trying to solve. We hired an employe with a long first and lastname combination. Our CUCM is integrated with Active Directory and was originally authenticating based on the samAccountName, but we found that using this field caused long usernames to be truncated so we removed our AD integration and re-integrated CUCM with AD based on userPrincipalName. Since authenticating based on userPrincipalName, we had to deploy a simple xml file to each user's computer to make the Jabber client work, however, we have not been able to get our linux / pidgin users working yet.